Machine for automatic placement of sliders and associated method

ABSTRACT

The invention concerns a machine ( 1 ) for automatic placement of sliders, including in particular:
         a first supplier ( 100 ) for supplying closure profiles ( 20 ), said closure profiles ( 20 ) being provided with complementary means ( 22 ) allowing the progression of the closure profiles ( 20 ) in said machine ( 1 );   a second supplier ( 200 ) for supplying sliders ( 10 );   a device ( 400 ) for placing sliders ( 10 ); and   a separator guide ( 300 ), situated opposite the device ( 400 ) for placing sliders, said guide ( 300 ) comprising a guide channel ( 310   a,    310   b ) in which the closure profiles ( 20 ) progress, the width of said channel ( 310   a,    310   b ) being smaller than the thickness of the closure means ( 22 ), such that when the profiles ( 20 ) are brought by the supply means ( 100 ) into the separator guide ( 300 ), the closure means ( 22 ) do not penetrate the guide channel ( 310   a,    310   b ) while the portion ( 23 ) underlying said closure means ( 22 ) is squeezed by the walls of the guide channel ( 310   a,    310   b ), in order to separate the respective free ends ( 21 ) of the closure profiles ( 20 ).

The present invention concerns the field of bags provided withcomplementary closure profiles actuated by a slider.

More particularly, the invention concerns a machine and method forplacing a slider on complementary closure profiles, provided to beattached on a bag.

Many bags of this type have already been proposed.

Known in particular are bags formed from thermoplastic sheets, forexample polyethylene and/or polypropylene.

As illustrated in FIG. 1, the closure profiles 20 used on such bagsgenerally comprise complementary closure means 22 situated respectivelyopposite on the two main sheets making up the bag to be respectivelymade to engage in order to close said bag and separated to allow itsopening.

The sliders 10 equipping such bags can be the subject of manyembodiments. Generally, such sliders 10 comprise a base 11 whichincludes two side flanks 12 and a central wall 13, the side flanks 12and the central wall 13 defining together two non-parallel channels 14which respectively receive free ends of profiles 20. In a direction ofmovement of the slider 10, the profiles 20 are stressed in separation toopen the bag. In the opposite direction of movement, the profiles 20 areengaged to close said bag.

In order for the slider 10 not to be easily removed from the bag, inparticular for safety reasons for children, it is usually provided withretaining means, for example of the flange type 15, arranged on the freeend of the wall 13, complementary with protuberances 21 forming a stopand situated on the free end of the profiles 20, such that in case ofattempt to tear the slider off of the bag, the flanges abut against theprotuberances 21 and prohibit removal of the slider 10.

One of the problems posed, however, in the field of closure profilesequipped with sliders, in particular when they comprise this type ofretaining means, is that of the engagement of the sliders on theseprofiles.

Means have therefore been proposed making it possible to elasticallydistance the flanks from the slider so that it can more easily beengaged on the complementary closure profiles, for example in Frenchpatent application FR 07 59545, filed Dec. 4, 2007 in the applicant'sname.

This technique indeed makes it possible to facilitate placement of theslider. However, it was noted that the free end 21 of the profiles 20could abut against the end 15 of the central wall 13 of the slider 10,especially when the latter part is provided with flanges, therebypreventing the insertion of the profiles 20 into the correspondingchannels 14 of the slider 10. Such a scenario is illustrated in FIG. 1,for example.

The present invention therefore aims to overcome this gap, by proposinga machine for the automatic placement of sliders and a method forplacing sliders, making it possible to facilitate the placement of aslider on closure profiles.

Thus, the present invention proposes a machine for automatic placementof sliders, including in particular:

-   -   a first supplier for supplying closure profiles, said closure        profiles being provided with complementary closure means        allowing the progression of closure profiles in said machine;    -   a second supplier for supplying sliders; and    -   a slider placement device;        also comprising a separator guide, situated opposite the slider        placement device, said guide comprising a guide channel in which        the closure profiles progress, the width of said channel being        smaller than the thickness of the closure means, such that when        the profiles are brought by the supply means into the separator        guide, the closure means do not penetrate the guide channel        while the portion underlying said closure means is squeezed by        the walls of the guide channel, in order to separate the        respective free ends of the closure profiles.

Preferably but non-limiting aspects of the automatic placement machineaccording to the invention are the following:

-   -   the width of the channel is essentially equal to the thickness        of the portion of the profiles that underlies the closure means,    -   the guide is a single piece, and the guide channel is a rabbet,    -   the guide is made up of two adjacent units, and their adjacent        walls are entirely or partially separated by the guide channel,    -   the separator guide units can move in a direction transverse to        the direction of movement of the closure profiles in the        machine,    -   the separator guide also includes a recess formed opposite the        placement device, at the mouth of the guide channel,    -   the recess has a hemispherical, conical or dihedral shape, the        concavity of which is oriented toward the placement device,    -   the materials making up the separator guide belong to the        following group: plastic, metal, and    -   the machine also comprises means for manufacturing a bag        equipped with closure profiles provided with a slider.

According to a second aspect of the invention, a method for placing aslider on closure profiles is proposed consisting of:

-   -   providing closure profiles, said closure profiles being provided        with complementary closure means, and having them progress in an        automatic slider placement machine;    -   providing sliders, said sliders comprising a base which includes        two side flanks and a central wall, the side flanks and the        central wall in combination defining two non-parallel channels        which respectively receive free ends of the profiles; and    -   sequentially engaging a slider on the closure profiles; the        method also including a step during which the respective ends of        the closure profiles are positioned opposite the corresponding        channels of the slider and separated by squeezing by a separator        guide of the portions of the closure profiles that underlie the        closure means, so as to facilitate the engagement of the slider        on said profiles.

Other features, aims and advantages will better appear upon reading thedetailed description that follows, and in light of the appended drawingsprovided as non-limiting examples in which:

FIG. 1 is a cross-sectional view of a slider and closure profiles duringengagement of the slider on the profiles according to the prior art;

FIG. 2 is a diagrammatic perspective view of a machine for manufacturingbags capable of being equipped with the automatic slider placementmachine according to the present invention;

FIG. 3 is a cross-sectional view of a slider and closure profiles uponengagement of the slider on the profiles according to one embodiment ofthe invention;

FIG. 4 is a cross-sectional view of a second embodiment of a separatorguide according to the invention;

FIG. 5 is a cross-sectional view of the first embodiment of a separatorguide illustrated in FIG. 3;

FIG. 6 is a cross-sectional view of a third embodiment of a separatorguide according to the invention; and

FIG. 7 is a cross-sectional view of a fourth embodiment of a separatorguide according to the invention.

The present invention can be applied to all types of bags. For thatreason, we will not describe all of the means for realizing the bagitself in detail hereinafter, or its component material(s).

The same is true for the closure profiles 20. They are not limited tothe geometry illustrated in the appended figures. These profiles 20 cancomprise closure means 22 of the male/female type, complementaryVelcro/hook type, or any other equivalent structure. They can be made inany suitable material.

The closure profiles 20 can be integral with the walls of the bag, forexample by extrusion, or attached and fixed on the walls of the bagusing any suitable means.

Lastly, the sliders 10 implemented in the framework of this inventionare of the type of the sliders we described in reference to FIG. 1 andwill therefore not be described in further detail hereinafter.

The guide according to the invention is preferably implemented in theframework of the automatic placement of sliders 10 on closure profiles20 to form thermoplastic bags. It is made in plastic or metal material,for example.

According to the invention, an automatic slider placement machine inparticular includes means for supplying closure profiles, progressionmeans of said profiles in the automatic machine, means for supplyingsliders and a slider placement device. Of course, the slider placementmachine can be part of a bag manufacturing, filling and closure machine,making it possible to manufacture bags equipped with closure profilesprovided with sliders using said placement machine of the invention.

One example of such a machine is illustrated in FIG. 2. Such a machine 1in particular comprises:

-   -   a first supplier 100 for supplying closure profiles 20;    -   a second supplier 200 for supplying sliders 10;    -   a device 400 for placing sliders 10, intended to sequentially        perform the individual placement of each slider 10 on the        profiles 20;    -   a third supplier 500 for supplying a thermoplastic film 30;    -   a shaping neck 600 associated with a filling chute 610, which        configures the film 30 from a flat initial state into a tube;    -   means 700 ensuring the longitudinal welding of the adjacent        longitudinal edges of the film 40 and the fastening of the        closure profiles 20 equipped with sliders 10 on the film 30; and    -   transverse welding clamps 800 associated with cutting means 900        in order to individualize the bags.

According to the invention, the machine also includes a separator guide300 arranged opposite the placement device 400, the role of which is, onone hand, to guide the closure profiles 20 during their progression inthe machine such that they arrive in an optimal position in front of theplacement device so that the sliders 10 can be correctly applied on theprofiles 20, and on the other hand, to separate the profiles 20 in orderto facilitate their engagement in the channels of the slider.

During the placement method of the sliders 10 on the closure profiles 20in the automatic machine 1, the placement device forcibly applies,conventionally, a slider 10 on the free end 21 of the closure profiles.

Preferably, the placement device separates the side flanks 12 from theslider 10, for example by stressing lugs situated on the outer faces ofthe side flanks of the slider (not shown in the figures), so as to freeenough space to allow the engagement of the profiles 20. Such a step isoptional inasmuch as the invention can be applied to any method forplacing a slider on closure profiles in which the slider is engaged onthe free end of the profiles.

In parallel, closure profiles 20 are brought into the separating guide,such that the free end 21 of each profile 20 is opposite correspondingchannels 14 of the slider 10.

Advantageously but not necessarily, the closure profiles 20 are closedwhen they are brought into the separator guide 300, or at least theirrespective closure means 22 are in contact with each other during theirpassage in the guide 300.

Separating the profiles 20 here means spacing the free ends 21 of theprofiles 20 that are intended to be arranged in the correspondingchannels 14 of the slider 10, such that said ends 21 move away from theplane defined by the closure profiles 20.

Indeed, it has been noted that when the ends 21 of the profiles 20 arenot parallel to each other and form an angle as illustrated in FIG. 2,the engagement of the slider 10 onto the closure profiles 21 is improveddue to the fact that said ends 21 avoid the obstacle formed by thecentral wall, and in particular get around the flange 15 of said wall,even if said ends 21 are provided with protuberances.

For this, the guide includes two essentially parallel stop walls forminga guide channel 310 a, 310 b of the profiles 20. The walls are arrangedsuch that the width of the channel 310 a, 310 b is essentially equal tothe thickness of the portion 23 of the closure profiles 20 underlyingthe closure means 22. Thus, the width of the guide channel 310 a, 310 bis smaller than the thickness of the closure means 22, which thereforedo not penetrate inside said channel 310 a, 310 b.

By pinching the portion 23 of the profiles underlying the closure means22, the stop walls cause the free end 21 of the profiles to move away byhinge effect, as indicated in FIG. 3. Indeed, given that the closuremeans 22 are in contact, and preferably closed, the pressure exerted onsaid underlying portion 23 drives the rotation of each free end 21around the axis formed by the closure means 22 in a separation directionrelative to the plane defined by the profiles 20. The ends 21 of theprofiles 20 are then no longer parallel to each other and present anangle that facilitates their insertion into the corresponding channelsof the sliders 10.

According to one preferred embodiment illustrated in FIGS. 3 to 5, theseparator guide 300 is cast in one piece, and the guide channel 310 a isa rabbet whereof the height is at least equal to the length of theportion 23 of the profiles extending under the closure means 22. Thewalls of said rabbet 310 a then correspond to the stop walls of theguide 300.

Alternatively, when the closure profiles 20 are integral with the wallsof the bag or have been attached to said walls prior to the insertion ofthe slider 10, the height of the rabbet 310 a is at least equal to thelength of the bag extending between its mouth and its bottom.

According to another embodiment illustrated in FIG. 7, the guide 300includes two adjacent units 300 a, 300 b and in contact over at leastpart of one of their walls, said walls forming said rabbet 310 a betweenthem.

Alternatively to this embodiment, as illustrated in FIG. 6, the units300 a, 300 b are adjacent but are not in contact, such that the guidechannel is no longer a rabbet but a through channel 310 b.

In the case where the separator guide 300 includes two adjacent units300 a, 300 b, said units 300 a, 300 b can be fixed or mobile in adirection transverse to the direction of the progression of the profiles20.

For example, in the case of a discontinuous manufacturing method, theautomatic machine sequentially stops the progression of profiles 20. Theunits 300 a, 300 b then close on the profiles 20 (while forming theguide channel 310 a, 310 b) and squeeze them so as to separate theirfree ends 21, while the placement device 400, simultaneously orsuccessively, engages the slider 10 on said separated ends 21. The units300 a, 300 b then move transversely to free the profiles and the machineresumes the progression of profiles 20.

One can also consider implementing units 300 a, 300 b mobile in theframework of a continuous manufacturing method, during which theprogression of profiles 20 is not interrupted. The units 300 a, 300 bare then sequentially closed on the profiles 20 during theirprogression, and the placement device 400 engages the slider 10simultaneously or successively to the pinching of the profiles 20,without interrupting the progression of profiles 20.

Once the slider 10 is engaged on the profiles 20, it is sufficient torelease the side flanks 12 of the slider 10, which elastically return totheir initial position, thereby enclosing the ends 21 of the profiles20.

Alternatively, as illustrated in FIGS. 2 to 5, the guide 300 alsoincludes a recess 320 at the mouth of the rabbet 310 a (or throughchannel 310 b formed by the units 300 a, 300 b), for examplehemispherical, conical or dihedral in shape, whereof the concavity isoriented toward the slider 10, in order to further accentuate theopening of the ends 21 under the pressure of the guide 300.

1. A machine for automatic placement of sliders, including inparticular: a first supplier for supplying closure profiles, saidclosure profiles being provided with complementary means allowing theprogression of the closure profiles in said machine; a second supplierfor supplying sliders a device for placing sliders; and a separatorguide, situated opposite the device for placing sliders, said guidecomprising a guide channel in which the closure profiles progress, thewidth of said channel being smaller than the thickness of the closuremeans, such that when the profiles are brought by the supply means intothe separator guide, the closure means do not penetrate the guidechannel while the portion underlying said closure means is squeezed bythe walls of the guide channel, in order to separate the respective freeends of the closure profiles.
 2. The automatic placement machineaccording to claim 1, wherein the width of the channel is essentiallyequal to the thickness of the portion of the profiles underlying theclosure means.
 3. The automatic placement machine of claim 1, whereinthe guide is a single piece, and the guide channel is a rabbet.
 4. Theautomatic placement machine of claim 1, wherein the guide is formed bytwo adjacent units, and that their adjacent walls are separated in wholeor in part by the guide channel.
 5. The automatic placement machine ofclaim 4, wherein the units of the separator guide are mobile in adirection transverse to the direction of movement of the closureprofiles in the machine.
 6. The automatic placement machine of claim 1,wherein the separator guide also includes a recess formed opposite theplacement device, at the mouth of the guide channel.
 7. The automaticplacement machine of claim 1, wherein the recess has a hemispherical,conical or dihedral shape, the concavity of which is oriented toward theplacement device.
 8. The automatic placement machine of claim 1, whereinthe component materials of the separator guide belong to the followinggroup: plastic, metal.
 9. The automatic placement machine of claim 1,further comprising means for manufacturing a bag equipped with closureprofiles provided with a slider.
 10. A method for placing a slider onclosure profiles, comprising the steps of: supplying closure profiles,said closure profiles being provided with complementary closure means,and making them progress in an automatic slider placement machine;supplying sliders, said sliders comprising a base (11) that includes twoside flanks and a central wall, the side flanks and the central walldefining, in combination, two non-parallel channels that respectivelyreceive free ends of the profiles; and sequentially engaging a slider onthe closure profiles; the method further including a step wherein therespective ends of the closure profiles are positioned opposite thecorresponding channels of the slider and separated by pinching by aseparator guide from the portions of the closure profiles underlying theclosure means, so as to facilitate the engagement of the slider on saidprofiles.